AVS Forum banner
Status
Not open for further replies.
1 - 18 of 18 Posts

·
Registered
Joined
·
42 Posts
Discussion Starter · #1 ·
have a question for anyone familiar with receivers and harmon kardon


im currently using them with mirage omni polar speakers i have bookshelf speakers for fronts and omni center both rated at 125 watts and 150 watts rms respectively.


im looking for a reciever that has a decent thd, i want clean sound, since i use it a lot for music. i hasitly bought a 5.1 pioneer vsx 411, thats rated at 1% thd and there was a white noise constantly that annoyed me. it ruined everythign the sound of anything that i used it to play


i had a kenwood 6070 but returned it because of defection, and there were no more units left at BB, that receiver had audio that was good enough for me to listen to music, but those receivers are disconued and sounded as if it was underpowering hte speakers since the level of sound quality jump dramatically after the volume knob passed the 2/5thhs mark


now im interested in harmon kardon, but i only have about 400-500 dollars to spend and i was look at hk's in that price range for 5.1

http://shop3.outpost.com/product/3335912


it has an output power of 45 watts per channel

http://shop3.outpost.com/product/3335922


or this one with 55 watts.


what frightens me is that the kenwood receiver was tested by sv magazine and they rated it at a constant 92 watts per channel x 6, so if the hk's are 55/45 watts are accurate, then will these receivers kill my speakers?

people have also told me that the hks are high current (i dont know if the models i listed are high current though)

and that the kenwood is low current, would that make any difference in powering/underpowering my speakers?


anyone know the answer?


sorry im pretty noob to the audio world, any help would be appreciated :)
 

·
Registered
Joined
·
707 Posts
As long as you configure all of your speaker to high-pass (SMALL) and redirect bass to a powered subwoofer, 50 watts per channel should be adequate for reasonably high listening levels. Probably not Dolby reference level, but close enough.
 

·
Registered
Joined
·
42 Posts
Discussion Starter · #3 ·
hwc, what is this clipping and underpowering mean then?


because i was informed that if i use a recevier that did not adquately supply enough watts ie (hk 55 watts) to a speaker ie omni (rms 150 watts) that the speaker will damage over time.


this is what scares me since the two book shelf speakers and center alone cost 1000 dollars and this took me a long time to save up (i know many og you get into multi thousand dollar systems but i dont have that much money ;) ). id hate to get a receiver that will damage them by underpowering.


it difficult to find a decent 5.1 receiver thatll actually provide decent power,


ive also read that underpowering a speaker is much more harmful then over driving them
 

·
Registered
Joined
·
707 Posts
Clipping an amplfier occurs when you ask it (with the volume control) to deliver more power than it is capable of producing. Clipping is dangerous for speakers because it generates distortion products that are rough on tweeters. However, clipping can only occur as a result of YOUR hand on the volume control and will usually show up as audible distortion long before you do any damage.


Go back to what I said about configuring your speakers as high-pass "small" and redirecting bass to a powered subwoofer. This removes a huge load from the receiver's amps because they are no longer playing any deep bass. Deep bass notes are what usually clips an amplifier, so configuring your system like this is similar to having a receiver with twice as much power. It can play its portion of the spectrum considerably louder without clipping.


But, wait, there's more..... Now when a bass note clips, it's only clipping the subwoofer amplifier. Our ears can't hear distortion in the deep bass very well, so the clipping is not paricularly noticeable. But, even better, the clipping can't send distortion products to the midrange and tweeter because they aren't even connected to the sub amp.


If you don't have a sub, 50 watts is probably a little underpowered for very high volume listening, but it should still play loud enough. But, there's no reason that you should damage any speakers if you don't drive the system into gross distortion. It's pretty hard to blow up modern loudspeakers with anything short of mindless, knuckle-dragging abuse.


All else being equal, a 100 watt amp will only play 3 dB louder than a 50 watt amp. 3 dB is a barely audible volume difference. For music listening, most of us play our systems using less than 5 watts of continuous power, so a 50 watt amplifier still has plenty of headroom without clipping.
 

·
Registered
Joined
·
42 Posts
Discussion Starter · #5 ·
i kinda get it, hwc thanks for the information sir, i have two powered 120 watts subs, i got them pretty cheap too two sawm 40 for 250 dollars total i think. with all my previous receivers ive listened to ive always had them on small or middle size. never large.


last night i picked up the vsx 411, on clearance, i thought this would be a good substitute for a couple of months until i find a decent receiver. but to my horror, there was a constant hiss and the high frequencies were distorted, when i didnt even play it at loud levels...


so this thing will be going back today, i detached the wretched device from the speakers quickly and boxed it up for tommorows refund. this thing said it was 100 watts per channel, and didnt power my speakers well,


so thats why im concerned about the harmon kardons 55 watts per channel:( if i do ge this receiver i plan on getting it online because its about 150 dollars cheaper to get it online, i wont be able to audition, so its all oor nothing. :(
 

·
Registered
Joined
·
707 Posts
Quote:
Originally posted by RnBfan
last night i picked up the vsx 411, on clearance, i thought this would be a good substitute for a couple of months until i find a decent receiver. but to my horror, there was a constant hiss and the high frequencies were distorted, when i didnt even play it at loud levels...
It was defective....or something. Probably fried outputs.


That is not something that any receiver would do if it is working properly, and it has nothing at all to do with the power output or the performance of Pioneer receivers in general.


For the money, I think Pioneer receivers are pretty good, no different than any of the other brands in similar price ranges. IMO, when you are talking sub $500 price ranges, a receiver is a receiver and you could just close your eyes and pick one.
 

·
Registered
Joined
·
1,646 Posts
Indeed. BTW, RnBfan, I'm glad your asking the "experts" here rather than at teamxbox.


When you talk about that noise with the 411, was it a hum or hiss. Was it audible at the listening position or only within a few inches of the tweeters? Do you have flourescent lighting on the same power circuit? How about light dimming light switches?
 

·
Registered
Joined
·
42 Posts
Discussion Starter · #8 ·
When you talk about that noise with the 411, was it a hum or hiss. Was it audible at the listening position or only within a few inches of the tweeters? Do you have flourescent lighting on the same power circuit? How about light dimming light switches?


hi sorny, i finally got around to registering here, i tend to keep posting here to minimum since information can get overwhelming for me here.


the noise i hear is a hiss, its a slight hiss its not apparent, i only notice it because the receiver i used before it had cleaner sound. i was told by my friends that its due to the pioneers total harmoic distortion, my ears are very sensitive btw, its strange i can hear over tones and undetones, and even the high pitch frequencies general electronic devices emit, (i learn to block noise like that out though.)


so what people may not notice, i notice it like a sore thumb. this is my first serious venture into audio components. i didnt realize it would become so expensive :(, i have no flourescent lighting either :(


i went to the good guys today and spoke with a sales person, and he told me that i shouldnt get the harmon kardon 55wx5 receiver because it will not be enough to power my speakers,

he recomended dennon receivers, pointing at one that was 110 watts, then i told him i remember reading somewhere that dennon tends to rate their receivers like that at 6ohms, so in reality it would only be about 80-90 watts at 8 ohms, and that the continous output on denon receivers are iffy.


wouold a dennon receiver be better then a harmon kardon? i can get a lot more features with a denon receiver in the 500 dollar price range, how about onkyo? personally i had bad experiences with onkyo, question their quality control and build quality of their receivers.
 

·
Registered
Joined
·
1,646 Posts
Is the hiss audible at your listening position? Every amp I have ever heard introduces hiss when powered on if you listen within a few inches of the tweeter (I am by no means an expert, and I have not listened to more than a handful of amps). That is normal in my experience. Hearing hiss at the listening position is NOT normal though.

My Sunfire Cinema Grand power amp is rated "200 watts rms continuous per channel, all channels driven into eight ohms from 20Hz to 20KHz with no more than 0.5% T.H.D.". Much higher than my Pioneer Elite VSX-45TX receiver (0.09%). Any guesses as to which sounds better? Yup, the Sunfire; as it should considering the price. Not all distortion is bad; the number of people who love tubes is proof enough of that. :D I preach accuracy, but have an amp that was deliberately "voiced" to have a certain sound. It is warm and a good mix for my tastes, which is what this whole "audio" thing is about... What I'm trying to say is that while specs are important to take into consideration, actually listening to the equipment will quickly tell you what you do and do not want.


When you bought your speakers, I assume you listened to them at the dealer, right? If you like how that sounded, why not get the receiver that drove the speakers?

As far as the sales drone at the good guys, he is an idiot; 55Wx5 from H/K is like 100Wx5 from other receivers (in this price range at least). The reason is that H/K is honest with their ratings, they are also conservative ratings. I doubt you would need more than 55W per channel, unless you want to reach Dolby reference volume. How big is the room you are set up in? Do you have subwoofers? If so, set your speakers to "small" in the receiver and let the subwoofers belch out the bass (bass takes enormous amounts of power to make); that way your receiver only needs to amp 80-20KHz, which is a much easier load, and thus, needs less power.


Denon has many die-hard fans, just like H/K. H/K is far more honest with power output, but you really shouldn't worry about the power. If your price range is up to $500, you should really look hard at the H/K 520 (last year's midrange model), or a refurb'd 525. It'll blow you away. The Sony 2ES can be had for around that price online as well. The bottom line is you need to listen to everything yourself, at your home, to determine what will work the best.


Sorny
 

·
Registered
Joined
·
707 Posts
Are you sure that you weren't listening to one of the Pioneer's DSP Music modes? JAZZ, DRAMA, HALL, THEATER, etc.? That is the only time I've every heard noisy output from my Pioneer. Quite the contrary, I find the thing to be remarkably quiet considering the fact that it's sitting smack dab up against a direct view TV and embedded in a rats next of equipment and cables.


It's not THD that you are hearing. You would have to have huge THD numbers, well above 1%, to be audible. A ground loop or "buzz" from your cable TV connection is a far more likely culprit. That can sound like a buzzsaw.
 

·
Registered
Joined
·
42 Posts
Discussion Starter · #11 ·
i dont know maybe, i havent tried more the 3 receivers, the last receiver i had was the kenwood 6070 for about a month, and thats pretty much the only receiver i can compare it to, i had the pioneer and kenwood models hooked up exactly the same way and same position and same speakers though, and the difference was so huge that i noticed the degrade in sound quality instantaneously, i unhooked the thing shortly after.


i was looking into the hk 525 last night, its about 700 dollars or so shipped, that may be better at powering the speakers? i dont plan on buying a seperate amplifier component though, that would be too expensive for me.


but the 225 has a very attracive price, it can be found for half the price of the 525 online.arrrgh,, hah, the 525 will take me a couple of monehts to save up, i have too many bills :(


maybe i should give up and just get the pioneer 912k? and live with it :) i wonder what the true power out specs are on that receiver.
 

·
Registered
Joined
·
42 Posts
Discussion Starter · #12 ·
see this is what frightens me, this is a comment made in another forum, i wont post the link but ill post the comment for some info to debate with.


"Harman Kardon is one of a very few manufactures that lists the watts while running 5 channels.

Does any one know if their listed watts for 5 channels is accurate? Based on test reports.

Onyko 600 is 34W per 5 channels, Onkyo 700 is 38w per 5 channels, Yamaha 1200 is 50W per 5 channels.


I would like to know the accurracy of HK listing.

My hats off to HK for listing what other manufactures do not"

--------------

I blew a pair of B & W speakers with an Onyko 600 receiver that put 16.5 volts (34w) to my speakers when they dmanded more. The speakers needed 50W to drive when a strong, loud signal is on the source.
 

·
Registered
Joined
·
42 Posts
Discussion Starter · #13 ·
this is a question for audiophiles techies here.


how does a speaker spl efficiency level and rms wattage corrolate with a recevers wattage all channels driven?


if my omni speakers have an efficeincy of 91 decibles per watt per meter, decibles rise in increments of x2,


then when you calculate


it would go like this


watts vs decible level(my fronts)

----------------------

1 watts -91 decibles

2 watts -94 decibles

4 watts -97 decibles

8 watts -100 decibles

16 watts -103 decibles

32 watts -106 decibles(dolby digital spl reference level reached)

64 watts -109 decibles

--------------

--------------


my center has a effiency of 90


then it would be

---------------------

1 watts -90

2 watts -93

4 watts -96

8 watts -99

16 watts -102

32 watts -105(dolby reference level)


it would take 32 watts of power to attain 104-106 decibles of sound.


how would this relate to the hk receiver avr 225?

and why do my speakers have an rms of 125 and 100 watts? how does this relate to receiver compatibilty?

how doest this relate (if any) to underpowering them?


so if the hk receiver has 50 watts per channel(i dont know how accurate it is, is the 225, 50 watts per channel x 5? or is it a total of 50 watts through 5 channels being used at once? i dont understand?


how does clipping come into play? and under what circumstances would cause my speakers to clip? im assuming if theres a spike in sound and the receiver required more then 105 decibles of sound at 32 watts that anyhting above 106 decibles in the spike would kill/harm my speakers tweeter?


why do speakers post rms watt ratings anyway? what does that mean? is comparing receiver wattst to speaker watts erroneous on my part?


does 125 rms just mean that the speaker is capable of playing about 112 decibles of sound? then why do people keep telling me that using a low wattage apmplifier/receiver will clip a speaker?


how loud is 105 decibles anyway? whats the average decible level a person would use for movie watching at a decent loud level?


how does high current and low current effect clipping? or quality of sound?



these are the specifications for the harmon receiver

---------------------
Audio


Stereo Mode Continuous Average Power (FTC) Per Channel: 65 Watts per channel, 20Hz – 20kHz, @
 

·
Registered
Joined
·
42 Posts
Discussion Starter · #14 ·
i have just dicovered a new term i do not understand now :(


minimum wattage to drive a speaker?


think the my speaker doesnt really need a minimum, the specs says


up to 125 watts

or

up to 150 watts


but when i look at the German part of the manual


it states the numbers


30-125 watts rms

30-150 watts rms


does this mean i need a minimum of 30 watts to drive this speaker?


does that mean i have to have my reciever constantly driving 30 watts when ever i listen use them?


or does it mean, that the receiver has to be capable of dishing out 30 watts when needed as a minimum?
 

·
Registered
Joined
·
707 Posts
Quote:
Originally posted by RnBfan
watts vs decible level(my fronts)

----------------------

1 watts -91 decibles

2 watts -94 decibles

4 watts -97 decibles

8 watts -100 decibles

16 watts -103 decibles

32 watts -106 decibles(dolby digital spl reference level reached)

64 watts -109 decibles

--------------
Good job! That's the correct theoretical model. There is one more thing though. That's at one meter from the speaker. Output falls of with square of distance. So if you sit at three meters from the speakers, subtract about 9 dB from each of those numbers. So 64 watts is now 100 dB at the listening position and you need 256 watts per channel to theoretically reach 106 dB. So, on paper, no receiver has sufficient continuous power to reach Dolby reference levels and very few speakers could handle that much power any way.


Fortunately, we don't listen "on paper" and the whole thing is nowhere near that cut and dried.


First of all, that goal of 105 dB is "digital full scale" the absolute loudest possible peak that can be recorded (all bits = 1s). A recording engineer never, ever wants an recorded signal to exceed that because gross digital distortion occurs in the recording. So, any sane engineer would actually make sure that the loudest peaks are several dB below that.


Second, we are talking about instantaneous short term peaks. In order to keep the short term peaks from exceeding the 105 dB limit, the average signal level (RMS, if you will) is recorded some 10 to 20 dB below that level. So, what we are really looking at on your chart is the ability to play at the 94 dB level on your chart (about 2 watts at 1 meter, about 16 watts at 3 meters). That's a realistic number for the continous RMS (average) power that you will be using when playing the system very loud.


Everything above that in terms of amplifier power is extra headroom so that the amp can play short term peaks without clipping. How much extra headroom is "enough" is very hard to quantify -- it depends on many factors, especially the behavior of the particular amplifier.


Now, it's even more complicated really. All of these numbers assume a constant impedance of 8 ohms. But, that's not how real speakers work. A real speaker has an impedance that varies from 3 ohms to perhaps 60 ohms depending on the frequency of the sound.


Real rooms don't behave like these models, because added to these numbers are reflected sounds from the walls and ceiling and reinforcement from adjacent surfaces.


Additionally, you have to figure the benefits of bi-amping and redirecting bass to a powered subwoofer. Amplifier clipping almost always occurs during low bass notes. But, with all of your speakers set to "small", the receiver amplifiers are not playing any bass notes. Thus, the amps can play much much louder without clipping. Any clipping that occurs will occur in the subwoofer amplifier and, because it's not even connected to any of your main speakers, no tweeter-killing distortion products are there to harm your main speakers, even when the system is being over-driven.


Bottom-line: in an ideal world with an all "small" system, I would like to have somewhere around 100 watts per channel on my satellites. But, an all things being equal, a 50 watt version of that same amplifier is only 3 dB quieter than the 100 watt version without clipping. 3dB is not very much.; it's a barely audible change in volume. In my opinion, an honest 50 watts per channel in an all-small system in a normal size room is adequate unless you play the system extremely loud and keep it there even when you start to hear signs of distress from the system (what I affectionately refer to as "knuckle-dragging abuse"). Double those numbers for amplifier power if you run your speakers as "large".


As for speaker wattages: they really don't mean anything. All they are intended to provide is a rough guide concerning the recommended size of the amplifier you should buy. So for your speakers, the recommendation is to use them with any amplifier between 30 watts per channel and 125 watts per channel. But, you probably already knew that before you even looked at the spec sheet.
 

·
Registered
Joined
·
42 Posts
Discussion Starter · #16 ·
hwc, i greatly appreciate your thrurough explainations, thank you!


sorny, thank you too!


if anyone else has any information to contribute please post, i need to learn as much as i can, so i dont accidentally destroy my audio equipment from ignorance :)
 

·
Registered
Joined
·
1,646 Posts
As a quick suggestion, you might want to use Avia or the THX optimizer (on starwars I & II, T2:UE, ID4, Fight Club, several other discs as well) to check your phase. I know phase mismatch shouldn't sound like a buzz, but it is worthwhile to check anyways. :D


Sorny
 

·
Registered
Joined
·
79 Posts
I'd like to add a couple of things that don't appear to have been mentioned.


Your room size plays a major part in how much power you need. It is true that sound dissipates as the square of the distance, but only in an anechoic chamber or outdoors. In a room sound reflects off of the walls, floor, and ceiling. If you have a small room less power is needed.


You can take the same amplifier and rate it a different wattage levels depending upon how much distortion you will accept, what the load impedance is, and how many channels you are driving. For this reason alone comparing wattage ratings among manufacturers is pretty much a waste of time unless there is a large difference ( more than 2X). As other posters have pointed out, double the power only means 3 DB difference in actual sound pressure level.


Any audible noise from a system at your listening position is not to be expected but almost all amplifiers will have some audible noise if you put your ear close to the speaker. Since it appears that you have had "hiss" with at least 2 receivers the receiver itself may not be the problem. If the "hiss" level changes with the volume control then it may be interference or noise from one of your input sources. Try to isolate the source of the noise before blaming the receiver. You can do this by disconnecting input sources etc and see when, if ever, the noise goes away. You may want to start with nothing but the receiver and speakers connected.


Clipping can cause damage to your speakers if you tend to play highly compressed music (such as rock) at a very high levels. If the amplifier does not have any "soft clipping" features then clipping of the waveform generates high frequency harmonics than can overdrive and burn out tweeters. Many of the harmonics are beyond audibility. As others have pointed out, this usually only happens when you have cranked up the volume to the point where there is some audible distortion but some listeners may not hear the distortion at these high levels. It is not likely though that the damage will occur slowly over time. Failure is usually sudden and happens during the high volume session when the voice coil of the tweeter overheats and opens or shorts. This happens to the tweeter because it has the smallest and most fragile drive coil. Higher power amplifiers reduce the likelihood of this happening.


The position of the volume control is meaningless in determining output power. Some manufacturers design the "taper" of the volume control to provide a lot of gain at the lower positions giving the user the illusion of more power than the amp actually has. Others make the volume control more linear so that the user has finer control over the level by using the entire rotation of the control as a usable range. In my opinion, the latter is preferred.
 
1 - 18 of 18 Posts
Status
Not open for further replies.
Top